While I was pausing the game to figure out how best to take a screenshot, a few times the game didn't pause when I pressed "ESC". The menu opened normally, only the game was still running in the background.

Great finds! - The first one doesn't have a proper bug report for v0.2.1, so I'll make one. The second issue is a known one, but you are one of the first to post about it. Reports do affect the priority of fixes, so this is very useful information. Thanks!